33 lines
628 B
Go
33 lines
628 B
Go
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// Copyright (C) 2018 Storj Labs, Inc.
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// See LICENSE for copying information.
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package readcloser
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import "io"
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// LazyReadCloser returns an ReadCloser that doesn't initialize the backing
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// Reader until the first Read.
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func LazyReadCloser(reader func() io.ReadCloser) io.ReadCloser {
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return &lazyReadCloser{fn: reader}
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}
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type lazyReadCloser struct {
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fn func() io.ReadCloser
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r io.ReadCloser
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}
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func (l *lazyReadCloser) Read(p []byte) (n int, err error) {
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if l.r == nil {
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l.r = l.fn()
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l.fn = nil
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}
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return l.r.Read(p)
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}
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func (l *lazyReadCloser) Close() error {
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if l.r != nil {
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return l.r.Close()
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}
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return nil
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}
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